Lubricating oils contain additives that perform many important functions. Ashless dispersants are added to lubricating oils to disperse varnish, lacquer, and sludge that may be formed in the oil and prevent the formation of deposits Ashless dispersants also disperse soot and prevent viscosity buildup caused by the agglomeration of soot in the oil. Overbased detergents are added to lubricating oils to neutralize acids. These acids can cause wear and corrosion, and can cause acid catalyzed reactions and rearrangements to occur in the oil. Anti-oxidants are added to lubricating oils to control oxidation of the oil by scavenging radicals or by decomposing hydroperoxides that are formed from the oxidation of the oil. Wear inhibitors are added to lubricating oils to prevent wear of the metal parts caused by friction. Other additives such as corrosion inhibitors, friction modifiers, viscosity index improvers, pour point depressants, seal, swell agents, etc., can also be added to lubricating oils to provide important properties to the finished lubricant.
Metal ions can play an important role in the deterioration of lubricating oils. Transition metals such as Fe+3, Cu+2, Pb+2, and other metals, can catalyze the oxidation of the oil resulting in the formation of the primary oxidation products such as hydroperoxides, carboxylic acids, carbonyl compounds, hydroxyl carbonyl compounds, and the like. In addition, metal ions such as Fe+3, Cu+2 Pb+2, and other metals, can catalyze the polymerization of the primary oxidation products resulting in the formation of sludge, lacquer, and varnish.
In order to prevent the metal catalyzed oxidation and polymerization of lubricating oils, it would be desirable to find a way to complex or sequester the metal ions and prevent the metal ions from acting as oxidation and polymerization catalysts.
Sequestering agents have many uses, in living plants for supplying necessary trace elements, in metal plating baths, removing rust stains, removing impurities and in fuels and lubricating oils. Most well known sequestering agents are useful only in aqueous media. There is a great need for good sequestering agents that are oil-soluble. Oil-soluble sequestering agents are also useful for the introduction of metals into non-aqueous systems, for providing oil-borne micro-nutrients to plants and many other uses known to persons skilled in the art. Oils useful for lubricating internal combustion engines are generally either mineral oils or synthetic oils of lubricating viscosity. Thus, sequestering agents for use in lubricating oils or hydrocarbon fuels must be oil-soluble.
The conventional oil-soluble Mannich condensation products are useful in internal combustion engine fuels. Non-volatile constituents of fuel, such as additives, sometimes form deposits or varnish on inlet valves and on heating elements. Such deposits and varnish impair the efficiency of these elements. In addition, fuels are susceptible to chemical reactions, such as, oxidation, on aging. One effect of oxidation is to produce soluble and insoluble materials that form deposits which interfere with the proper functioning of the internal combustion engines. The conventional oil-soluble Mannich condensation products help to reduce deposits.
Oil-soluble Mannich condensation products are also useful in internal combustion engine lubricating oils. These products generally act as dispersants to disperse sludge, varnish, and lacquer, and prevent the formation of deposits. In general, conventional oil-soluble Mannich condensation products are formed from the reaction of polyisobutyl-substituted phenols with formaldehyde and an amine or a polyamine. These products have limited ability to sequester Fe+3 and have limited ability to prevent the Fe+3 catalyzed oxidation and polymerization that often occur.
Water soluble Mannich condensation products are well known as sequestering agents. However, such products cannot be used as sequestering agents in fuels and lubricating oils.
The preparation of Mannich condensation products is well known in the art. A number of patents disclose Mannich condensation products of alkylphenols, aldehydes and amines. However, none of the known Mannich condensation products contain both the needed oil solubility and the ability to sequester Fe+3 to prevent Fe+3 catalyzed oxidation and polymerization reaction in lubricating oil.
U.S. Pat. No. 4,032,304 discloses an improved fuel composition containing a normally liquid fuel, a carboxylic acid ester of lubricating viscosity and an oil-soluble nitrogen-containing dispersant. The dispersant is characterized by the presence therein of a substantially saturated hydrocarbon-based radical having at least 50 carbon atoms. The dispersant is preferably a carboxylic dispersant or a Mannich-type dispersant. The Mannich-type dispersant is for example the reaction product of an alkylphenol with formaldehyde and a polyethylene polyamine.
U.S. Pat. No. 4,069,249 discloses a novel Mannich condensation product chelating agent for iron (III) or iron (II). The chelating agent is a Mannich condensation product made from phenol or substituted-phenol, formaldehyde, a di-amino di-acid and a di-amine. The process for making these Mannich condensation products is disclosed in U.S. Pat. No. 4,338,460.
U.S. Pat. No. 4,166,726 discloses a fuel additive and fuel composition. The additive compound is a mixture of a polyisobutylene amine and the reaction product of an alkylphenol, an aldehyde and an amine. The additive provides surprising stability in preventing thermal degradation of fuels, particularly fuels for compression ignition engines.
U.S. Pat. No. 4,116,991 discloses an aromatic chelating agent having a hydroxyl group at the center of the molecule. Such chelating agents have better stability in an alkaline environment.
U.S. Pat. No. 4,130,582 discloses a process for the preparation of phenolic ethylenediamine polycarboxylic acids in predominantly the ortho isomeric form which comprises reacting a phenol compound, ethylenediamine, glyoxylic acid and a base, said phenol compound functioning both as a reactant and as a solvent for the reaction system.
U.S. Pat. No. 4,197,091 discloses a composition for inhibiting the corrosion of ferrous metal pipelines used to transport petroleum hydrocarbons comprising a major portion of a mixture of C36 di-carboxylic dimer acid and a C54 trimer add, which mixture has an acid number of at least 110 and from 0.5 up to 5% of a composition from the group consisting of (a) an N,N′-di(ortho-hydroxyarylidene)-1,2-alkyldiamine in which the arylidene radical contains 6-7 carbon atoms and the alkylene radical contains 2-3 carbon atoms; and (b) a polymeric condensation product obtained by the reaction of a phenol having two reactive ring positions, a lower aliphatic aldehyde and a polyamine.
U.S. Pat. No. 4,225,502, a division of application Serial No. 630,792, U.S. Pat. No. 4,069,249 discussed above, discloses a novel Mannich condensation product chelating agent for iron (III) or iron (II). The chelating agent is a Mannich condensation product made from phenol or substituted-phenol, formaldehyde, a di-amino di-acid and a di-amine. The single claim is to a cyano-substituted compound.
U.S. Pat. No. 4,200,545 discloses combinations of amino phenols, wherein said phenols contain a substantially saturated hydrocarbon substituent of at least 10 aliphatic carbon atoms, and one or more detergent/dispersants selected from the group consisting of (I) neutral or basic metal salts of an organic sulfur acid, phenol or carboxylic acid; (II) hydrocarbyl-substituted amines wherein the hydrocarbyl substituent is substantially aliphatic and contains at least 12 carbon atoms; (III) acylated nitrogen-having compounds having a substituent of at least 10 aliphatic carbon atoms; and (IV) nitrogen-having condensates of a phenol, aldehyde and amino compound. Fuels and lubricants having such combinations as additives are particularly useful in two-cycle (two-stroke) engines.
U.S. Pat. No. 4,387,244 discloses that alkyl-substituted hydroxybenzyl amino acid oligomers are effective metal chelating agents in a broad range of non-aqueous systems. The products claimed display surprisingly high solubilities in a broad range of substituted and unsubstituted aliphatic and aromatic solvents.
U.S. Pat. No. 4,655,949 discloses a novel lubricating oil composition comprising an organometallic additive, including a metal selected from Groups I, Ib and VIII of the Periodic System of Elements, e.g. Na, K, Cu, Co, Ni or Fe, chelated with the reaction product of formaldehyde, an amino acid and a phenol, dissolved in a lubricating oil. Depending on the choice of metal, the above organometallic additive imparts rust inhibition, sludge dispersant, wear reduction and anti-oxidant properties to the said lubricating oil.
U.S. Pat. No. 4,734,212 discloses Bis-Mannich base deposit inhibitors; lubricating oil compositions having these inhibitors and a process for preparing these inhibitors.
U.S. Pat. No. 4,847,415 discloses certain Mannich reaction products (i.e. alkylated phenol, polyoxyalkylenediamine, and an aldehyde) which are used to deactivate iron species already present in hydrocarbon fluids. Left untreated, such iron species lead to decomposition resulting in the formation of gummy, polymer masses in the hydrocarbon liquid. The method for the preparation of these Mannich condensation products are claimed in the divisional U.S. Pat. No. 4,883,580.
U.S. Pat. No. 4,894,139 discloses certain Mannich reaction products formed from the reaction of an alkyl-substituted catechol, a polyamine and an aldehyde which are used to deactivate copper metal species contained in hydrocarbon fluids. Left untreated, such species lead to decomposition resulting in the formation of gummy, polymer masses in the hydrocarbon liquid.
U.S. Pat. No. 5,122,161 discloses a diesel fuel composition comprising (a) a major portion of a diesel fuel, and (b) a minor amount, as a diesel fuel injector detergent, of a glycolated Mannich coupled product of bis-polyisobutylene succinimide of a polyamine, prepared by: (i) reacting an alkylsuccinic add anhydride with a polyamine to form a bis-succinimide; (ii) reacting the bis-succinimide with a phenol in the presence of an aldehyde to form a Mannich phenol coupled bis-succinimide product; (iii) glycolating the Mannich phenol coupled bis-succcinimide product with glycolic acid to form a glycolated Mannich phenol coupled bis-succinimide product; and (iv) recovering the glycolated Mannich phenol coupled bis-succinimide product.
U.S. Pat. No. 5,641,394 discloses a composition for use in deactivating iron species in hydrocarbon fluids, comprising the products resulting from the reaction of (I) a substituted-catechol, (II) a mixture of polyamines, and (III) an aldehyde. The composition also functions as an anti-oxidant in hydrocarbon fluids. The anti-oxidant function is separate from, and in addition to the metal deactivating properties of the invention. These functional properties of the invention can act either singly, or in concert, for stabilization of hydrocarbon fluids.
An article titled “Preparation of Amphiphilic Polyisobutylenes-b-polyethylenamines by Mannich Reaction. III. Synthesis of Polyisobutylenes-b-polyethylenamines,” by J. D. Jamois, M. Tessier and E. Marechal, Journal of Polymer Science Part A: Polymer Chemistry, Vol. 31, 1959-1966 (1993) discloses preparation of copolymers associating alpha-phenololigoisobutylene and triethylenetetramine blocks in the same chain by reacting aqueous formaldehyde with alpha-phenololigoisobutylene and triethylenetetramine.